Sponge-fishing, disease and farming in the Mediterranean Sea

Some Mediterranean sponge species belonging to the genera Spongia and Hippospongia, have been harvested for commercial purposes since ancient times. Recently, a widespread epidemic has greatly reduced the density of sponge populations which has had serious repercussions in the commercial field. 2. The synergetic action of harvesting and disease has taken a number of populations to the brink of extinction. Sponge-population densities are steadily decreasing and their recovery after the disease event is incomplete and has taken a long time. 3. There is a simple solution to the problem: sponge-farming. Trials have been underway since the beginning of the century and recently, Cuba, the Philippines and Micronesia Islands have started commercial sponge-farming. 4. Sponges are naturally able to remove dissolved organic matter, organic particles and bacteria from the water-column and this ability could be exploited in an integrated mariculture system. Floating cages for fish production result in the release of a lot of organic wastes that can be used as a source of food for surrounding intensive commercial sponge communities. Such an integrated system could result in effective eutrophication control, commercial sponge production and a consequent reduction of fishing effort on already heavily-stressed natural sponge populations.